Frequencies for first 10,000 rows of air_bag variable in person dataset :

    AIR BAG |
AVAILABILIT |
 Y/FUNCTION |      Freq.     Percent        Cum.
------------+-----------------------------------
          0 |        667        6.67        6.67
          1 |      1,147       11.47       18.14
          2 |          5        0.05       18.19
          8 |          3        0.03       18.22
          9 |          5        0.05       18.27
         20 |        435        4.35       22.62
         28 |          6        0.06       22.68
         29 |      1,653       16.53       39.21
         30 |      5,867       58.67       97.88
         31 |          3        0.03       97.91
         99 |        209        2.09      100.00
------------+-----------------------------------
      Total |     10,000      100.00

by Jean Roth , jroth@nber.org , 18 Apr 2016